Sterility and partial sterility in the South African clawed toad following the pricking of the egg

Development ◽  
1970 ◽  
Vol 23 (2) ◽  
pp. 375-384
Author(s):  
Mia L. Buehr ◽  
Antonie W. Blackler
Keyword(s):  
South African ◽  
Rana Temporaria ◽  
Original Position ◽  
Developmental History ◽  
Partial Sterility ◽  
Vegetal Pole ◽  
Frog Rana Temporaria ◽  
History Of ◽  
A Cell ◽  
Early Gastrula

Bounoure (1934) first described the presence in the egg of the frog Rana temporaria of a special cytoplasmic differentiation, which he termed the ‘germinal cytoplasm’. He was able to trace the developmental history of this plasm as it moved from its original position just under the cortex of the vegetal pole of the fertilized egg, to its inclusion in a number of cells of the early gastrula endoderm, and also mapped the migration of these cells into the gonad rudiments. Bounoure believed that the germinal cytoplasm is the definitive germcell determinant, and that its presence in a cell is a prerequisite for the cell to undergo meiosis and differentiate into a gamete. Since Bounoure's discovery, germinal cytoplasm has been described in the eggs of a number of other anuran species (Nieuwkoop, 1956; Blackler, 1958; DiBerardino, 1961; Gipouloux, 1962) and a number of techniques have been used to test Bounoure's determinant hypothesis.

scholarly journals European common frog (Rana temporaria) recolonised Switzerland from multiple glacial refugia in northern Italy via trans- and circum-Alpine routes

2019 ◽  
Author(s):  
A Jansen van Rensburg ◽  
M Robin ◽  
B C Phillips ◽  
J Van Buskirk
Keyword(s):  
Western Europe ◽  
Rana Temporaria ◽  
Phylogenetic Analyses ◽  
Glacial Refugia ◽  
Interesting Case ◽  
Northern Italy ◽  
High Mountain ◽  
European Alps ◽  
Frog Rana Temporaria ◽  
History Of

AbstractThe high mountain ranges of western Europe have had a profound effect on the recolonisation of Europe from glacial refugia. The Alps present a particularly interesting case, because they present an absolute barrier to dispersal to most lineages, obstructing recolonisation from multiple refugia in the Italian Alps. Here we investigate the effect of the European Alps on the the phylogeographic history of Rana temporaria across its range in Switzerland. Based on partial cytochrome b and COX1 sequences we find two mitochondrial lineages that occur roughly north and south of the alpine ridge bisecting Switzerland, with contact zones between them in the east and west. The northern haplogroup falls within the previously identified common western European haplogroup, while the southern haplogroup is unique to Switzerland. We find that the lineages diverged ~110 kya, approximately the onset of the last glacial maximum, indicative of origins in separate refugia. Phylogenetic analyses suggest that the lineages originate from two refugia in northern Italy, and colonised Switzerland via trans- and curcum-alpine routes. Our results show that the European Alps is a semi-permeable barrier to dispersal for R. temporaria, and have contributed to the complex recolonisation history of Switzerland.

A History of Ethical Codes in South African Psychology: An Insider's View

1998 ◽  
Vol 28 (3) ◽  
pp. 135-145 ◽  
Author(s):  
Douglas R. Wassenaar
Keyword(s):  
South Africa ◽  
South African ◽  
Professional Ethics ◽  
Future Trends ◽  
Developmental History ◽  
Ethical Codes ◽  
History Of ◽  
The Relationship

The purpose of this article is to present a developmental history of formal professional ethics in psychology in South Africa. Particular emphasis is placed on the relationship between legislation governing the registration of psychologists and professional ethics. Current and future trends emphasising the need to transform professional structures in keeping with the democratic ethos of post-apartheid South Africa are also discussed.

scholarly journals The Ecology and Life History of the Common Frog (Rana temporaria temporaria)

Copeia ◽  
1962 ◽  
Vol 1962 (3) ◽  
pp. 667 ◽  
Author(s):  
Richard G. Zweifel ◽  
R. Maxwell Savage
Keyword(s):  
Life History ◽  
Rana Temporaria ◽  
Common Frog ◽  
Frog Rana Temporaria ◽  
History Of ◽  
The Common

Investigations of the Germ-plasm in Relation to Nuclear Transplantation

Development ◽  
1961 ◽  
Vol 9 (3) ◽  
pp. 507-513
Author(s):  
Marie A. Di Berardino
Keyword(s):  
Germ Cells ◽  
Germ Plasm ◽  
Rana Temporaria ◽  
Primordial Germ Cells ◽  
Nuclear Transplantation ◽  
Early Cleavage ◽  
Large Size ◽  
Vegetal Pole ◽  
Frog Rana Temporaria ◽  
Made In

The origin of the germ-cells has been extensively investigated in both invertebrates and vertebrates. In invertebrates it has been traced to the early cleavage of the zygote, e.g. in such forms as Ascaris megalocephala (Boveri, 1887) and Sciara (Metz, 1938). Within the vertebrate group the cases in which primordial germ-cells have been detected in cleavage stages are very few. Eigenmann (1891) identified gonocytes of Micrometrus aggregates in the late gastrula stage on the basis of their large size and the uniform distribution of their chromatin. The first clear demonstration of vertebrate primordial germ-cells appearing in a stage as early as the blastula was made in the European frog, Rana temporaria (Bounoure, 1934). In this case germ-cells were found to be conspicuous because of a stainable cytoplasmic element, the germ-plasm. This germ-plasm first appears shortly after fertilization in the form of islets concentrated in the vegetal pole region of the egg (Bounoure, 1934, 1939, 1954).

The First Record of Tesselated Snake, Natrix tesselata Laurenti, 1768 in the Central Chernozem Territory of Russia and Some Other Results of the Herpetological Research in the Upper Don

2011 ◽  
Vol 4 (2) ◽  
pp. 192-194
Author(s):  
Georgy A. Lada ◽  
V. Y. Nedosekin
Keyword(s):  
Rana Temporaria ◽  
First Record ◽  
Isolated Population ◽  
Common Frog ◽  
Northern Border ◽  
Frog Rana Temporaria ◽  
Bombina Bombina ◽  
Central Chernozem

A small isolated population of tesselated snake, Natrix tesselata was found in the Upper Don (Lipetsk Region, Russia). It is the first record of this species in the Central Chernozem Territory of Russia, which is separated from the northern border of the main range by the distance of about 200 km. An isolated population of common frog, Rana temporaria and phenetically peculiar population of fire-bellied toad, Bombina bombina are found here too. Faunistic aspect of new herpetological records is discussed.

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